‘Red BG’ is a new and distinct variety of apple tree (Malus domestica Borkh), which variety originated as a limb sport mutation of ‘Granny Smith’ (not patented). ‘Red BG’ was discovered by the inventor in a cultivated orchard at Stanthorpe, Queensland, Australia in 2013, and was selected for further observation because of the distinctive red overcolor. ‘Red BG’ was first asexually propagated by budding in 2013 at Grove, Tasmania, Australia, and has since been observed to remain true to type over successive asexually propagated generations.